1. Field of the Invention
The present invention relates in general to a method for producing micro-optical components. More particularly, it relates to a method for dispensing very small and precise amounts of optical materials for producing micro-optical components.
2. Description of the Prior Art
The increasing demands in miniaturization and parallel processing of optoelectronic devices and the maturity of the process technologies in micron-scale fabrication have pushed forward the development of microlenses and other micro-optical components. According to the lens performance principles utilized, the various types of microlenses developed to date can be categorized as refractive lenses, diffractive lenses or mixed refractive/diffractive lenses. Refractive lenses bend or focus a light beam by rules of geometric optics. Diffractive lenses alter the path of light based on Fourier optics. Mixed refractive/diffractive lenses typically include refractive lenses having the surface thereof textured with diffracting patterns to correct for chromic aberrations.
Current techniques for fabricating micro-optic components include fiber end-surface etching; fiber tip etching and melting; laser micromachining; fiber drawing; polymer island melting; localized UV radiated and heated photothermal glass; ion-beam etching of Si; ion-beam etching of InP; chemical etching of InP; graded index finishing techniques such as ion exchange in glass from molten salt, swelling the surface of glass, chemical vapor deposition of SiH.sub.4 and NO, and ion-beam sputtering of Si-O-N; and binary optics techniques including the use of 2-step Fresnel phase plates, 8-step Fresnel phase plates and blazed reflection grooves.
Small scale lenses offer performance advantages in faster optics and reduced aberrations. Individual lenses formed on the tips of optical fibers and on diode lasers in addition to arrays of lenses, have been demonstrated with reasonable performance characteristics, particularly for coupling into or out of fibers, detectors and diode lasers. Arrays of refractive lenslets have been used to provide efficient coupling of arrays of energy sources to amplifier and detector arrays or to bundles of optical fibers. In addition, telescopes, waveguides, couplers, relays, and spot generators incorporating small scale lenses have been investigated. Materials which have been used for forming such small scale lenses include glass, silicon, indium phosphide, polymers including amorphous Teflon.RTM. and plastics.
The production of such microlenses, however, has been severely limited by the above-mentioned techniques. The present invention provides a solution to various prior art drawbacks and deficiencies including the lack of flexibility in micro-optics manufacture and the inability to print micro-optical components directly onto optical substrates and devices.